(Edit 14 may: warning: this method will be obsolete as soon as the Gnome 3 RPMs are merged into the main Tumbleweed repo, so you should check whether that’s happened).
There is a Tumbleweed repo containing Gnome 3 RPMs, located at this address:
http://download.opensuse.org/repositories/openSUSE:/Tumbleweed:/GNOME/openSUSE_Tumbleweed
The package manager (@gregkh of these forums) intends soon to fold all the RPMs into the Tumbleweed repo so that a special repo for Gnome packages will no longer be required. But until this happens, that is the repo that you can attach if you want to upgrade your Tumbleweed with Gnome 2 to Tumbleweed with Gnome 3.
Here’s the process I used, written as a HowTo:
First, before you attach the Gnome 3 repo, prepare your Tumbleweed for Gnome 3 by making it fully up to date in two steps. Step one is to get the existing security fixes and so on for the underlying 11.4 up to scratch by running Yast Online Update (go to Yast → Software → Online Updates). Step two is to upgrade the RPMs from the Tumbleweed repo with this command
zypper dup --from Tumbleweed
After making Tumbleweed up to date, attach and enable the Tumbleweed:Gnome repo (see address above). You can use Yast → Software → Software Reops to add it. I named the repo TumbleweedGnome (for example). So now you should have the original 11.4 repo enabled along with your primary Tumbleweed repos and the new Gnome repo, like this:
john@tumbleweed114:~> zypper lr -u
# | Alias | Name | Enabled | Refresh | URI
---+----------------------+------------------------+---------+---------+------------------------------------------------------------------------------------------
1 | Tumbleweed | Tumbleweed | Yes | Yes | http://download.opensuse.org/repositories/openSUSE:/Tumbleweed/standard/
2 | TumbleweedPackman | TumbleweedPackman | Yes | Yes | http://packman.inode.at/suse/openSUSE_Tumbleweed
3 | repo-non-oss | openSUSE-11.4-Non-Oss | Yes | Yes | http://download.opensuse.org/distribution/11.4/repo/non-oss/
4 | repo-oss | openSUSE-11.4-Oss | Yes | Yes | http://download.opensuse.org/distribution/11.4/repo/oss/
5 | TumbleweedGnome | TumbleweedGnome | Yes | Yes | http://download.opensuse.org/repositories/openSUSE:/Tumbleweed:/GNOME/openSUSE_Tumbleweed
Then you simply run the update command with focus on the new Gnome repo,:
zypper dup --from TumbleweedGnome
When I ran the “zypper dup --from TumbleweedGnome” I got one dependency issue (not an error – an issue that was easy to solve). You might not get the issue, depending on what you had installed beforehand. Here’s the message I got:
Problem: libgdata7-0.6.6-2.1.i586 requires libgdata-lang = 0.6.6, but this requirement cannot be provided
and here’s the resolution suggested by zypper
Solution 22: install libgdata-lang-0.6.6-2.1.noarch from excluded repository
I accepted this and all proceeded smoothly. When the process finishes, the final step is to install three extra packages, shown below:
zypper in gnome-shell metatheme-adwaita-common gnome-shell-lang
Then reboot and it’s done.